This invention relates to an improved antenna beam switching system for use with a radar system such as a range-gated, pulse doppler radar system.
My prior patent application, Ser. No. 973,642, entitled "RADAR ANTENNA" filed Dec. 26, 1978 and now issued as U.S. Pat. No. 4,237,464, describes an antenna system comprising two antenna elements wherein the direction of the beam can be switched between two coplanar positions by means of a switch associated with the phase shifting means in one of the antenna element feed lines.
In this application, on the other hand, antenna system embodiments are disclosed which incorporate three antennas each with corresponding phase shifters and which, by means of suitable shunting of at least some of said phase shifters, permits three-dimensional beam switching in at least four different directions in space.